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A079216 Square array A(n>=0,k>=1) (listed antidiagonally: A(0,1)=1, A(1,1)=1, A(0,2)=1, A(2,1)=2, A(1,2)=1, A(0,3)=1, A(3,1)=3, ...) giving the number of n-edge general plane trees fixed by k-fold application of Catalan Automorphisms A057511/A057512 (Deep rotation of general parenthesizations/plane trees). 14
1, 1, 1, 2, 1, 1, 3, 2, 1, 1, 5, 5, 2, 1, 1, 6, 11, 3, 2, 1, 1, 10, 26, 8, 5, 2, 1, 1, 11, 66, 18, 11, 3, 2, 1, 1, 18, 161, 43, 30, 5, 5, 2, 1, 1, 21, 420, 104, 82, 6, 14, 3, 2, 1, 1, 34, 1093, 273, 233, 15, 38, 5, 5, 2, 1, 1, 35, 2916, 702, 680, 36, 111, 6, 11, 3, 2, 1, 1, 68, 7819, 1870 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

Note: the counts given here are inclusive, e.g. A(n,6) includes the counts A(n,3) and A(n,2) which in turn both include A(n,1).

LINKS

A. Karttunen, Catalan Automorphisms

Index entries for sequences related to parenthesizing

FORMULA

A(0, k) = 1. A(n, k) = Sum_{r=1..n where r/gcd(r, k) divides n} Sum_{c as each composition of n/(r/gcd(r, k)) into gcd(r, k) parts} Product_{i as each composant of c} A(i-1, lcm(r, k))

MAPLE

with(combinat, composition); # composition(n, k) gives ordered partitions of integer n into k parts.

[seq(A079216(n), n=0..119)]; A079216 := n -> A079216bi(A025581(n), A002262(n)+1);

A079216bi := proc(n, k) option remember; local r; if(0 = n) then RETURN(1); else RETURN(add(PFixedByA057511(n, k, r), r=1..n)); fi; end;

PFixedByA057511 := proc(n, k, r) option remember; local ncycles, cyclen, i, c; ncycles := igcd(r, k); cyclen := r/ncycles; if(0 <> (n mod cyclen)) then RETURN(0); else add(mul(A079216bi(i-1, ilcm(r, k)), i=c), c=composition(n/cyclen, ncycles)); fi; end;

CROSSREFS

A(n, A003418(n)) = A000108(n). The first row: A057546, second: A079223, third: A079224, fourth: A079225, fifth: A079226, sixth: A079227. Cf. also A079217-A079222.

Sequence in context: A098805 A168396 A049286 * A181654 A192710 A112380

Adjacent sequences:  A079213 A079214 A079215 * A079217 A079218 A079219

KEYWORD

nonn,tabl

AUTHOR

Antti Karttunen (His-Firstname.His-Surname(AT)gmail.com) Jan 03 2002

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Last modified February 13 08:12 EST 2012. Contains 205451 sequences.